forked from osmocom/wireshark
d47551982b
Mirror it after protocol dissector API. Change-Id: I7985bcfa9e07654c7cf005efec94efc205d7a304 Reviewed-on: https://code.wireshark.org/review/18496 Reviewed-by: Michael Mann <mmann78@netscape.net>
415 lines
13 KiB
C
415 lines
13 KiB
C
/* packet-chdlc.c
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* Routines for Cisco HDLC packet disassembly
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*
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* Wireshark - Network traffic analyzer
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* By Gerald Combs <gerald@wireshark.org>
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* Copyright 1998 Gerald Combs
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version 2
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* of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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*/
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#include "config.h"
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#include <epan/packet.h>
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#include <epan/capture_dissectors.h>
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#include <wsutil/pint.h>
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#include <epan/etypes.h>
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#include <epan/prefs.h>
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#include <epan/chdlctypes.h>
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#include <epan/nlpid.h>
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#include <epan/addr_resolv.h>
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#include "packet-chdlc.h"
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#include "packet-ppp.h"
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#include "packet-ip.h"
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#include "packet-juniper.h"
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#include "packet-l2tp.h"
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#include <epan/expert.h>
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/*
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* See section 4.3.1 of RFC 1547, and
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*
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* http://www.nethelp.no/net/cisco-hdlc.txt
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*/
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void proto_register_chdlc(void);
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void proto_reg_handoff_chdlc(void);
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void proto_register_slarp(void);
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void proto_reg_handoff_slarp(void);
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static int proto_chdlc = -1;
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static int hf_chdlc_addr = -1;
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static int hf_chdlc_control = -1;
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static int hf_chdlc_proto = -1;
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static int hf_chdlc_clns_padding = -1;
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static gint ett_chdlc = -1;
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static int proto_slarp = -1;
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static int hf_slarp_ptype = -1;
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static int hf_slarp_address = -1;
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static int hf_slarp_netmask = -1;
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static int hf_slarp_mysequence = -1;
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static int hf_slarp_yoursequence = -1;
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static int hf_slarp_reliability = -1;
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static expert_field ei_slarp_reliability = EI_INIT;
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static gint ett_slarp = -1;
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/*
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* Protocol types for the Cisco HDLC format.
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*
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* As per the above, according to RFC 1547, these are "standard 16 bit
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* Ethernet protocol type code[s]", but 0x8035 is Reverse ARP, and
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* that is (at least according to the Linux ISDN code) not the
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* same as Cisco SLARP.
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*
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* In addition, 0x2000 is apparently the Cisco Discovery Protocol, but
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* on Ethernet those are encapsulated inside SNAP with an OUI of
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* OUI_CISCO, not OUI_ENCAP_ETHER.
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*
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* We thus have a separate dissector table for Cisco HDLC types.
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* We could perhaps have that table hold only type values that
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* wouldn't be in the Ethernet dissector table, and check that
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* table first and the Ethernet dissector table if that fails.
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*/
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#define CISCO_SLARP 0x8035 /* Cisco SLARP protocol */
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static dissector_table_t subdissector_table;
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static capture_dissector_handle_t ip_cap_handle;
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static const value_string chdlc_address_vals[] = {
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{CHDLC_ADDR_UNICAST, "Unicast"},
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{CHDLC_ADDR_MULTICAST, "Multicast"},
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{0, NULL}
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};
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const value_string chdlc_vals[] = {
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{0x2000, "Cisco Discovery Protocol"},
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{ETHERTYPE_IP, "IP"},
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{ETHERTYPE_IPv6, "IPv6"},
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{CISCO_SLARP, "SLARP"},
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{ETHERTYPE_DEC_LB, "DEC LanBridge"},
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{CHDLCTYPE_BPDU, "Spanning Tree BPDU"},
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{ETHERTYPE_ATALK, "Appletalk"},
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{ETHERTYPE_AARP, "AARP"},
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{ETHERTYPE_IPX, "Netware IPX/SPX"},
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{ETHERTYPE_ETHBRIDGE, "Transparent Ethernet bridging" },
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{CHDLCTYPE_OSI, "OSI" },
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{ETHERTYPE_MPLS, "MPLS unicast"},
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{ETHERTYPE_MPLS_MULTI, "MPLS multicast"},
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{0, NULL}
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};
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gboolean
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capture_chdlc( const guchar *pd, int offset, int len, capture_packet_info_t *cpinfo, const union wtap_pseudo_header *pseudo_header) {
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if (!BYTES_ARE_IN_FRAME(offset, len, 4))
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return FALSE;
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switch (pntoh16(&pd[offset + 2])) {
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case ETHERTYPE_IP:
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return call_capture_dissector(ip_cap_handle, pd, offset + 4, len, cpinfo, pseudo_header);
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}
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return FALSE;
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}
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void
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chdlctype(guint16 chdlc_type, tvbuff_t *tvb, int offset_after_chdlctype,
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packet_info *pinfo, proto_tree *tree, proto_tree *fh_tree,
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int chdlctype_id)
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{
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tvbuff_t *next_tvb;
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int padbyte;
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proto_tree_add_uint(fh_tree, chdlctype_id, tvb,
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offset_after_chdlctype - 2, 2, chdlc_type);
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padbyte = tvb_get_guint8(tvb, offset_after_chdlctype);
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if (chdlc_type == CHDLCTYPE_OSI &&
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!( padbyte == NLPID_ISO8473_CLNP || /* older Juniper SW does not send a padbyte */
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padbyte == NLPID_ISO9542_ESIS ||
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padbyte == NLPID_ISO10589_ISIS)) {
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/* There is a Padding Byte for CLNS protocols over Cisco HDLC */
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proto_tree_add_item(fh_tree, hf_chdlc_clns_padding, tvb, offset_after_chdlctype, 1, ENC_BIG_ENDIAN);
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next_tvb = tvb_new_subset_remaining(tvb, offset_after_chdlctype + 1);
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} else {
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next_tvb = tvb_new_subset_remaining(tvb, offset_after_chdlctype);
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}
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/* do lookup with the subdissector table */
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if (!dissector_try_uint(subdissector_table, chdlc_type, next_tvb, pinfo, tree)) {
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col_add_fstr(pinfo->cinfo, COL_PROTOCOL, "0x%04x", chdlc_type);
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call_data_dissector(next_tvb, pinfo, tree);
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}
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}
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static gint chdlc_fcs_decode = 0; /* 0 = No FCS, 1 = 16 bit FCS, 2 = 32 bit FCS */
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static int
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dissect_chdlc(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
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{
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proto_item *ti;
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proto_tree *fh_tree = NULL;
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guint16 proto;
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col_set_str(pinfo->cinfo, COL_PROTOCOL, "CHDLC");
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col_clear(pinfo->cinfo, COL_INFO);
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switch (pinfo->p2p_dir) {
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case P2P_DIR_SENT:
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col_set_str(pinfo->cinfo, COL_RES_DL_SRC, "DTE");
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col_set_str(pinfo->cinfo, COL_RES_DL_DST, "DCE");
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break;
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case P2P_DIR_RECV:
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col_set_str(pinfo->cinfo, COL_RES_DL_SRC, "DCE");
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col_set_str(pinfo->cinfo, COL_RES_DL_DST, "DTE");
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break;
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default:
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col_set_str(pinfo->cinfo, COL_RES_DL_SRC, "N/A");
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col_set_str(pinfo->cinfo, COL_RES_DL_DST, "N/A");
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break;
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}
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proto = tvb_get_ntohs(tvb, 2);
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if (tree) {
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ti = proto_tree_add_item(tree, proto_chdlc, tvb, 0, 4, ENC_NA);
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fh_tree = proto_item_add_subtree(ti, ett_chdlc);
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proto_tree_add_item(fh_tree, hf_chdlc_addr, tvb, 0, 1, ENC_NA);
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proto_tree_add_item(fh_tree, hf_chdlc_control, tvb, 1, 1, ENC_NA);
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}
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decode_fcs(tvb, pinfo, fh_tree, chdlc_fcs_decode, 2);
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chdlctype(proto, tvb, 4, pinfo, tree, fh_tree, hf_chdlc_proto);
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return tvb_captured_length(tvb);
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}
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void
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proto_register_chdlc(void)
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{
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static hf_register_info hf[] = {
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{ &hf_chdlc_addr,
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{ "Address", "chdlc.address", FT_UINT8, BASE_HEX,
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VALS(chdlc_address_vals), 0x0, NULL, HFILL }},
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{ &hf_chdlc_control,
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{ "Control", "chdlc.control", FT_UINT8, BASE_HEX,
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NULL, 0x0, NULL, HFILL }},
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{ &hf_chdlc_proto,
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{ "Protocol", "chdlc.protocol", FT_UINT16, BASE_HEX,
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VALS(chdlc_vals), 0x0, NULL, HFILL }},
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{ &hf_chdlc_clns_padding,
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{ "CLNS Padding", "chdlc.clns_padding", FT_UINT8, BASE_HEX,
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NULL, 0x0, NULL, HFILL }},
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};
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static gint *ett[] = {
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&ett_chdlc,
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};
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module_t *chdlc_module;
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proto_chdlc = proto_register_protocol("Cisco HDLC", "CHDLC", "chdlc");
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proto_register_field_array(proto_chdlc, hf, array_length(hf));
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proto_register_subtree_array(ett, array_length(ett));
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/* subdissector code */
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subdissector_table = register_dissector_table("chdlc.protocol",
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"Cisco HDLC protocol", proto_chdlc,
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FT_UINT16, BASE_HEX);
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register_dissector("chdlc", dissect_chdlc, proto_chdlc);
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/* Register the preferences for the chdlc protocol */
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chdlc_module = prefs_register_protocol(proto_chdlc, NULL);
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prefs_register_enum_preference(chdlc_module,
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"fcs_type",
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"CHDLC Frame Checksum Type",
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"The type of CHDLC frame checksum (none, 16-bit, 32-bit)",
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&chdlc_fcs_decode,
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fcs_options, ENC_BIG_ENDIAN);
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register_capture_dissector("chdlc", capture_chdlc, proto_chdlc);
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}
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void
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proto_reg_handoff_chdlc(void)
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{
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dissector_handle_t chdlc_handle;
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capture_dissector_handle_t chdlc_cap_handle;
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chdlc_handle = find_dissector("chdlc");
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dissector_add_uint("wtap_encap", WTAP_ENCAP_CHDLC, chdlc_handle);
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dissector_add_uint("wtap_encap", WTAP_ENCAP_CHDLC_WITH_PHDR, chdlc_handle);
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dissector_add_uint("juniper.proto", JUNIPER_PROTO_CHDLC, chdlc_handle);
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dissector_add_uint("l2tp.pw_type", L2TPv3_PROTOCOL_CHDLC, chdlc_handle);
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chdlc_cap_handle = find_capture_dissector("chdlc");
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capture_dissector_add_uint("wtap_encap", WTAP_ENCAP_CHDLC, chdlc_cap_handle);
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ip_cap_handle = find_capture_dissector("ip");
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}
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#define SLARP_REQUEST 0
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#define SLARP_REPLY 1
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#define SLARP_LINECHECK 2
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static const value_string slarp_ptype_vals[] = {
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{SLARP_REQUEST, "Request"},
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{SLARP_REPLY, "Reply"},
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{SLARP_LINECHECK, "Line keepalive"},
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{0, NULL}
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};
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static int
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dissect_slarp(tvbuff_t *tvb, packet_info *pinfo, proto_tree *tree, void* data _U_)
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{
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proto_item *ti;
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proto_tree *slarp_tree;
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guint32 code;
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guint32 addr;
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guint32 mysequence;
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guint32 yoursequence;
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proto_item* reliability_item;
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col_set_str(pinfo->cinfo, COL_PROTOCOL, "SLARP");
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col_clear(pinfo->cinfo, COL_INFO);
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code = tvb_get_ntohl(tvb, 0);
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ti = proto_tree_add_item(tree, proto_slarp, tvb, 0, 14, ENC_NA);
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slarp_tree = proto_item_add_subtree(ti, ett_slarp);
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switch (code) {
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case SLARP_REQUEST:
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case SLARP_REPLY:
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addr = tvb_get_ipv4(tvb, 4);
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col_add_fstr(pinfo->cinfo, COL_INFO, "%s, from %s, mask %s",
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val_to_str(code, slarp_ptype_vals, "Unknown (%d)"),
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get_hostname(addr), tvb_ip_to_str(tvb, 8));
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if (tree) {
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proto_tree_add_uint(slarp_tree, hf_slarp_ptype, tvb, 0, 4, code);
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proto_tree_add_item(slarp_tree, hf_slarp_address, tvb, 4, 4, ENC_BIG_ENDIAN);
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proto_tree_add_item(slarp_tree, hf_slarp_netmask, tvb, 8, 4, ENC_BIG_ENDIAN);
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}
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break;
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case SLARP_LINECHECK:
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mysequence = tvb_get_ntohl(tvb, 4);
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yoursequence = tvb_get_ntohl(tvb, 8);
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col_add_fstr(pinfo->cinfo, COL_INFO,
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"%s, outgoing sequence %u, returned sequence %u",
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val_to_str(code, slarp_ptype_vals, "Unknown (%d)"),
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mysequence, yoursequence);
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proto_tree_add_uint(slarp_tree, hf_slarp_ptype, tvb, 0, 4, code);
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proto_tree_add_uint(slarp_tree, hf_slarp_mysequence, tvb, 4, 4,
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mysequence);
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proto_tree_add_uint(slarp_tree, hf_slarp_yoursequence, tvb, 8, 4,
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yoursequence);
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reliability_item = proto_tree_add_item(slarp_tree, hf_slarp_reliability, tvb,
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12, 2, ENC_BIG_ENDIAN);
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if (tvb_get_ntohs(tvb, 12) != 0xFFFF) {
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expert_add_info(pinfo, reliability_item, &ei_slarp_reliability);
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}
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break;
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default:
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col_add_fstr(pinfo->cinfo, COL_INFO, "Unknown packet type 0x%08X", code);
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proto_tree_add_uint(slarp_tree, hf_slarp_ptype, tvb, 0, 4, code);
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call_data_dissector(tvb_new_subset_remaining(tvb, 4), pinfo, slarp_tree);
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break;
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}
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return tvb_captured_length(tvb);
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}
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void
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proto_register_slarp(void)
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{
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expert_module_t* expert_slarp;
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static hf_register_info hf[] = {
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{ &hf_slarp_ptype,
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{ "Packet type", "slarp.ptype", FT_UINT32, BASE_DEC,
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VALS(slarp_ptype_vals), 0x0, NULL, HFILL }},
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{ &hf_slarp_address,
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{ "Address", "slarp.address", FT_IPv4, BASE_NONE,
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NULL, 0x0, NULL, HFILL }},
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/* XXX - need an FT_ for netmasks, which is like FT_IPV4 but doesn't
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get translated to a host name. */
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{ &hf_slarp_netmask,
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{ "Netmask", "slarp.netmask", FT_IPv4, BASE_NETMASK,
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NULL, 0x0, NULL, HFILL }},
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{ &hf_slarp_mysequence,
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{ "Outgoing sequence number", "slarp.mysequence", FT_UINT32, BASE_DEC,
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NULL, 0x0, NULL, HFILL }},
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{ &hf_slarp_yoursequence,
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{ "Returned sequence number", "slarp.yoursequence", FT_UINT32, BASE_DEC,
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NULL, 0x0, NULL, HFILL }},
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{ &hf_slarp_reliability,
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{ "Reliability", "slarp.reliability", FT_UINT16, BASE_HEX,
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NULL, 0x0, NULL, HFILL }},
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};
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static gint *ett[] = {
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&ett_slarp,
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};
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static ei_register_info ei[] = {
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{ &ei_slarp_reliability, { "slarp.reliability.invalid", PI_MALFORMED, PI_ERROR,
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"Reliability must be 0xFFFF", EXPFILL }}
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};
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proto_slarp = proto_register_protocol("Cisco SLARP", "SLARP", "slarp");
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proto_register_field_array(proto_slarp, hf, array_length(hf));
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proto_register_subtree_array(ett, array_length(ett));
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expert_slarp = expert_register_protocol(proto_slarp);
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expert_register_field_array(expert_slarp, ei, array_length(ei));
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}
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void
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proto_reg_handoff_slarp(void)
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{
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dissector_handle_t slarp_handle;
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slarp_handle = create_dissector_handle(dissect_slarp, proto_slarp);
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dissector_add_uint("chdlc.protocol", CISCO_SLARP, slarp_handle);
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}
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/*
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* Editor modelines - http://www.wireshark.org/tools/modelines.html
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*
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* Local Variables:
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* c-basic-offset: 2
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* tab-width: 8
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* indent-tabs-mode: nil
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* End:
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*
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* ex: set shiftwidth=2 tabstop=8 expandtab:
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* :indentSize=2:tabSize=8:noTabs=true:
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*/
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